CH622276A5 - - Google Patents

Description

The present invention relates to a novel thermosetting resin composition which has a polyfunctional epoxy compound containing a polyglycidyl ester of a fatty acid, a polyfunctional isocyanate compound and a curing catalyst.

The achievement of both excellent thermal resistance and excellent thermal shock resistance has so far encountered great difficulties with casting resins for larger components, such as rotating windings or rotors for high-performance electrical machines, transformer coils or the like. In particular, a low thermal shock resistance leads to the disadvantage that cracks form when hardening or undergoing temperature cycles. In general, a resin with excellent heat resistance is hard and accordingly has low thermal shock resistance. Casting resins for use with larger apparatus must, however, have a heat resistance of at least class F (155 ° C); So far, mainly alicyclic epoxy resins have been used for this. The thermal shock resistance was improved by adding inorganic fillers to reduce the coefficient of linear expansion of the entire casting resin and correspondingly reduce the difference in the coefficient of linear expansion between the resins and the casting device. However, this method is limited in that the fluidity of the resin composition decreases with increasing filler content.

It was therefore considered to soften the resin composition by adding a flexibilizer, but the problem with this method was that the heat distortion temperature was lowered and the heat resistance was deteriorated.

DE-OS 2 359 386 specifies a thermosetting resin composition which consists essentially of one equivalent of a polyfunctional epoxy compound, 1.5-5.0 equivalents of a polyfunctional isocyanate compound and a catalyst. When this thermosetting resin composition is heated to a temperature of 80 ° C or above, isocyanurate and oxazolidone rings are formed, and three-dimensional crosslinking and

Hardening. In this way, excellent heat resistance (class H = 180 ° C) and excellent mechanical strength at high temperatures can be achieved, which was previously not possible with thermosetting resins according to the prior art.

However, the cured product is unsatisfactory in terms of its thermal shock resistance as a casting resin for use in large apparatus. Especially when the high amount of 54 vol.% Filler is mixed in and the resulting composition according to the so-called "C-disk" method (modified method according to Olyphant, Minnesota Mining & Mfg. Co; described in "Thermal Shock Test for Castings, Proceedings , First National Conference on the Application of Electrical Insulation, Ohio, USA, September 1958 ”(explained in more detail later) was subjected to a thermal shock test, cracks occurred in the temperature cycles at 180 to -30 ° C. Adding such large amounts of filler is questionable from a practical point of view, since such compositions are difficult to flow.

DE-OS 2 440 953 describes a process for improving the thermal shock resistance of thermosetting resins with excellent heat resistance, in which an oxazolidone prepolymer with terminal epoxy groups is used as the polyfunctional epoxy compound component, which is obtained by reacting a diisocyanate compound with a stoichiometric excess of a diepoxy compound -dung is preserved. According to this method, flexibility required when applying films or layers of paints and varnishes or the like can be achieved, but the products do not have sufficient thermal shock resistance to be able to be used as casting resins for use in large apparatus, such as this is intended in the case according to the invention. Since casting resins also require freedom from solvents and the viscosity of such a prepolymer is too high for use in the absence of a solvent, this method is also hardly suitable for practical use.

The invention has for its object to provide a thermosetting resin composition with excellent heat resistance, which also has excellent thermal shock resistance.

The task is solved by a novel thermosetting resin composition which has the following components:

a) 1 equivalent, based on an isocyanate compound present, of a polyfunctional epoxy compound which contains 10-80% by weight of a polyglycidyl ester of a fatty acid,

b) 1.5-5 equivalents, based on the epoxy compound mentioned, a polyfunctional isocyanate compound,

c) 0.01-10% by weight of a curing catalyst, based on the total weight of the polyfunctional epoxy compound and the polyfunctional isocyanate compound.

By heating the thermosetting resin composition according to the invention, cured products with excellent heat resistance and excellent thermal shock resistance are accessible, which are suitable as molds or casting materials for use in large apparatus.

Drawing:

1 microphotograph of the cured product of Example 2,

2 cast-in C-shaped disc test piece for examining the thermal shock resistance of thermosetting resins,

3 temperature cycle diagram for the above test piece for testing the thermal shock resistance,

Fig. 4 used in the test of Example 33 model coil for rotating machines.

2nd

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

As described above, according to the method using oxazolidone prepolymers, parts are formed in the polymer that have no cross-linking points created by the oxazolidone prepolymer, thereby improving the flexibility of the polymer. However, this method is limited and does not lead to satisfactory thermal shock resistance in cast resins for larger apparatus, as is the basis of the invention.

As a result of extensive studies to improve the thermal shock resistance, it was found that a satisfactory thermal shock resistance cannot be achieved by the prepolymer method, since the crosslinking density due to the trimerization of an isocyanate is high and the resin is consequently hard; The invention is accordingly based on the consideration that in order to really improve the properties of the resins or for the production of parts with rubber elasticity, it is necessary to introduce straight-chain portions into the polymer.

As a result, it was found that the object according to the invention can be achieved by compositions which have the following components:

a) equivalent, based on the isocyanate compound (b), of a polyfunctional epoxy compound which contains 10-80% by weight of a polyglycidyl ester of a fatty acid,

b) 1.5-5 equivalents, based on the epoxy compound, of a polyfunctional isocyanate compound and c) 0.01-10% by weight of a curing catalyst, based on the total weight of the polyfunctional epoxy compound and the polyfunctional isocyanate compound.

After curing, the composition according to the invention shows the cross section shown in FIG. 1. A solid resin part, which mainly consists of a polyfunctional epoxy compound and a polyfunctional isocyanate compound, forms a matrix in which a flexible resin portion, which consists essentially of a polyglycyl ester of a fatty acid and a polyfunctional isocyanate compound, is evenly distributed in the form of fine beads. The product is very similar to acrylic acid-butadiene-styrene copolymers (ABS resins) or high-impact polystyrene. This macroscopic structure is believed to provide both heat resistance and thermal shock resistance.

However, when the amount of the polyglycidyl ester of the fatty acid in the polyfunctional epoxy compound exceeds 80%, the state of the two portions is reversed and the heat resistance suddenly decreases. Although this composition shows a state as in FIG. 1 after hardening, the composition is mutually uniformly dissolved before hardening and varies depending on the proximity of the gel point. Such a uniformly dispersed state can accordingly only be achieved if the components are compatible with one another when mixed together.

The polyglycidyl ester of the fatty acid contained according to the invention can be prepared by known processes, for example by epoxidizing a polyfunctional fatty acid prepared by polymerizing an unsaturated fatty acid with at least one unsaturated bond in the presence of a free radical initiator with an epihalohydrin.

The polyglycidyl ester contained according to the invention can also be prepared by epoxidizing a dimer obtained from an unsaturated fatty acid with at least two unsaturated bonds and an unsaturated fatty acid with at least one unsaturated bond by the Diels-Alder reaction with an epihalohydrin.

The following acids, for example, can be used as such unsaturated fatty acids with an unsaturated bond

3,622,276

are: 4-decenoic acid, caproleinic acid, lindenic acid, lauroleic acid, tsuzuic acid, myristoleic acid, palmitoleic acid, petroselinic acid (cis-6-octadecenoic acid), oleic acid, vaccenic acid (trans-ll-octadecenoic acid), gadoleic acid (gas doleic acid) , Erucic acid, Seiacholeic acid (selacholeic acid) or the like. For example, linoleic acid, linolenic acid, elaeosteraric acid, parinaric acid, arachidonic acid or the like can also be used as unsaturated fatty acid with two unsaturated bonds. The number of carbon 10 atoms in the polyfunctional fatty acid is preferably in the range of 25-43. If it is less than 25, the thermal shock resistance becomes poor. On the other hand, if it is over 43, the compatibility between the respective components deteriorates when mixed together. 15 The amount of the fatty acid polyglycidyl ester mixed with the polyfunctional epoxy compound is 10-80% by weight, preferably 10-60% by weight, in order to achieve a heat resistance corresponding at least to class H (180 ° C.).

20 In order to achieve compositions which can withstand temperatures of -50 ° or below in the thermal shock test according to the “C-disk” method described below, a quantity range of 20-60% by weight is favorable.

The following compounds, for example, can be used as polyfunctional epoxy compound: Bifunctional compounds such as diglycidyl ether of bisphenol A, diglycidyl ether of butanediol, diglycidyl ester of phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid and 4,4'-adnadic acid, methyladadic acid, methyladadic acid, and 4,4'-dadic acid, methyladadic acid, 4,4'-dadic acid, methyladadic acid, , 2-epoxyethyl) diphenyl, diglycidyl ether of resorcinol, phloroglucin, methylphloroglucin or the like as well as tri- or higher functional epoxy compounds such as triglycidyl ether of p-aminophenol, polyarylglycidyl ether, 1,3,5-tri- (1,2- epoxyethylbenzene), 2,2 ', 4,4'-tetraglycidoxybenzophenone, 35 tetraglycidoxybenzophenone, tetraglycidoxytetraphenyl ether, polyglycidyl ether of triglycidyl ether of glycerol and trimethylolpropyl ether, triglycidyl ether.

40 From the point of view of heat resistance, diglycidyl ethers of bisphenol A, diglycidyl esters of phthalic acid, isophthalic acid and terephthalic acid and polyglycidyl ethers of phenol novolack resins are particularly advantageous.

The following compounds can also be used, for example, as polyfunctional isocyanate: bifunctional isocyanates such as methane diisocyanate, butane-1, 1-diisocyanate, ethane-1, 2-diisocyanate, butane-1, 2-diisocyanate, propane

1,3-diisocyanate, 2-butene-l, 4-diisocyanate, 2-methylbutane

1,4-diisocyanate, pentane-1,5-diisocyanate, 2,2-dimethylpen-

50 tan-l, 5-diisocyanate, hexane-l, 6-diisocyanate, heptane-l, 7-diiso-cyanate, octane-l, 8-diisocyanate, nonane-l, 9-diisocyanate, de-can-l, 10 -diisocyanate, dimethylsilane diisocyanate, diphenylsilane diisocyanate, cu, a> '- l, 3-dimethylbenzene diisocyanate, oj, oj' ~ 1,4-dimethylbenzene diisocyanate, cu, oj'-1,3-dimethylcyclo -55 hexane diisocyanate, vj, oj '-1,4-dimethylcyclohexane diisocyanate, w, cu'-1,4-dimethylnaphthalene diisocyanate, co, w' -1,5-dimethylnaphthalene diisocyanate, cyclohexane-l , 3-diisocyanate, cyclo-hexane-l, 4-diisocyanate, dicyclohexyImethane-4,4'-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-60 benzene-2,4-diisocyanate, l -Methylbenzene-2,5-diisocyanate, 1-methylbenzoI-2,6-diisocyanate, l-methylbenzene-3,5-diisocyanate, diphenyl ether-4,4'-diisocyanate, diphenyl ether-2,4'-di-isocyanate , Naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, diphenyl-4,4'-diisocyanate, 3,3'-dimethyldiphenyl-4,4'-65 diisocyanate, 2,3'-dimethoxydiphenyl 4,4'-diisocyanate, diphenylmethane 4,4'-diisocayan at, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-dimethoxydiphenylmethane-3,3'-diisocyanate, diphenyl sulfide-4,4'-diisocyanate, diphenyl sulfone-4,4'-di-

622 276

4th

isocyanate or the like, and trifunctional or higher-functional isocyanates such as polymethylene polyphenyl isocyanates, tris (4-phenylisocyanate) thiophosphate, 3,3 ', 4,4' -diphenyimethane tetraisocyanate or the like.

Dimers and trimers of these isocyanates can also be used. Aromatic isocyanates are particularly useful from the standpoint of heat resistance.

The equivalent ratio of polyfunctional epoxy compound to polyfunctional isocyanate is in the range from 1: 1.5 to 1: 5.0. If the ratio is less than 1: 1.5, the strength at high temperatures and the heat deformation properties of the cured product are remarkably deteriorated. On the other hand, if the ratio exceeds 1: 5.0, the cured product becomes brittle and shows less thermal shock resistance.

The catalyst plays an important role in the compositions according to the invention. The so-called hetero-ring-forming catalysts, which form isocyanurate and oxazolone rings during curing, are of importance here. Suitable catalysts of this type are, for example, tertiary amines such as trimethylamine, triethylamine, tetramethylbutane diamine, tetramethylpentanediamine, tetramethylhexanediamine or the like, and also hydroxyalkylamines such as dimethylaminoethanol, dimethylaminopentanol or the like and various amines such as dimethylanilomethylphenol (30-phenol) -dimidol (30-phenol) -dimidol-dimphenol (30-phenol) -dimidol-tri-dimol N-methylmorpholine, N-ethylmorpholine, triethyl-diamine or the like.

Also useful are quaternary ammonium salts having a long-chain alkyl group of 8 or more carbon atoms such as cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, Dodecyltrimethylammo-niumjodid, trimethyldodecylammonium, Benzyldime-thyltetradecylammoniumchlorid, Benzyldimethylpalmitylam-ammonium chloride, dodecyl trimethyl ammonium bromide, benzyl dimethylstearylammoniumbromid, Stearyltrimethylammo-niumchlorid, Benzyldimethyltetradecylammoniumacetat od ..., Also also imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-methyl-4-ethylimidazole, l-butylimidazole, l-propyl-2-methylimidazole, l-benzyl -2-methylimidazole, l-cyanoethyl-2-methylimidazole, l-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, l-azine-2-methylimidazole, l-azine-2-ethylimidazole, l -Azine-2-undecylimidazole or the like.

At least one of the above-mentioned catalysts leading to hetero rings is present in an amount of 0.01-10% by weight, based on the weight of the mixture of the polyfunctional epoxy compound and the polyfunctional isocyanate compound.

In order to further improve the thermal shock resistance in the sense of the present invention, an inorganic filler for reducing the coefficient of thermal expansion can also preferably be present. Suitable fillers of this type are fillers already used, such as silica or silicon dioxide, aluminum oxide, diatomaceous earth, glass powder, quartz glass powder, mica, clay, calcium carbonate, gypsum, magnesite, kaolin, talc, dolomite, graphite, carbon black, iron carbonyl, asbestos, cement, Whisker, zircon, ferrite, molybdenum disulfite, zinc white, titanium white or the like.

The amount of the inorganic filler mixed can be up to 60% by volume, based on the volume of the total composition; in the case of a casting resin, however, the amount is preferably in the range of 45-55% by volume in view of the fluidity of the resin.

Furthermore, if a coupling agent is contained to improve the compatibility between the inorganic filler and the resin, the viscosity of the casting resin is reduced, which leads to improved processability and an increase in the moisture resistance of the shaped body after curing. Epoxysilane and aminosilane coupling agents are preferably used as such coupling agents.

The compositions according to the invention are cured by heating to 50-250 ° C. Particularly in cases where large parts of the apparatus are cast or molded, the hardening is preferably carried out slowly in the first stages at 70-130 ° C in order to reduce tensions during the hardening and to avoid the formation of cracks or cracks . The compositions are kept in this state at least until gelation occurs, after which curing is completed by heating to 150-200 ° C.

The thermal shock tests were carried out in such a way that a C-shaped disc 1 (see FIG. 2) with the resin 2 to be examined was first cast in and the resulting test piece was then subjected to the temperature cycles shown in FIG. 3 until Cracks occurred.

The above method using the C-shaped 20 disks is a modification of the aforementioned disk method specified by Olyphant; In the “C-disk” process used, an incision was made accordingly in the Olyphant disks in order to reduce the dispersion in the Olyphant disk process, which gave the disks a C-shape for 2 seconds. For this purpose, 4 mm wide incisions were made in unalloyed steel rings with an outer diameter of 40 mm, an inner diameter of 15 mm and a thickness of 5 mm, which resulted in correspondingly C-shaped-looking disks. By pouring the 30 C-shaped disks with the resin to be used, test pieces with an outside diameter of 57 mm and a thickness of 11 mm were produced. The test pieces were successively introduced into thermostats which were adjusted to the set temperatures or heated the test piece in accordance with the temperature cycle diagram shown in FIG. 3.

The invention is explained in more detail below with the aid of examples.

Examples 1-3

A bisphenol A epoxy resin (DER-332, manufacturer Dow 40 Chemical Co., epoxy equivalent 174), diglycidyl ester of linoleic acid dimer (Diels-Alder adduct, EP 871, manufacturer Shell Co., epoxy equivalent 430), diphenylmethane diisocyanate ( MDI, Sumidur CD, manufacturer Sumitomo-Bayer Co.) and 2-heptadecylimidazole were mixed in the proportions given in Table 1 for the preparation of 4Sser compositions according to the invention. The C-shaped disks were cast with these compositions to produce three test pieces, which were then subjected to the temperature cycle test. The curing conditions were 50110 ° C / 5 h, 140 ° C / 8 h and finally 180 ° C / 15 h.

Furthermore, the heat distortion temperature (HDT) was measured in accordance with ASTM D 648-45 T and the bending strength in accordance with JIS K-6911.

The results obtained are shown in Table 2.

Table 1

60

DER-332 (g)

EP 871 (g)

MDT (g)

2-heptadecylimidazole (g)

example 1

80

20th

210

1.5

Example 2

50

50

166

1.3

Example 3

20th

80

124

1.1

65 comparison

example 1

100

240

1.7

Comparative

example 2

100

96

1.0

5

Table 2

622 276

Temperature cycle test: Flexural strength Young (Flex) - HDT deflection

Crack formation per cm2 at break (%) module (° C)

temperature (° C) at 25 ° C

example 1

-10

1120

4.5

4.0 X104

> 220

Example 2

-40

890

5.6

3.0 X104

220

Example 3

-20

670

9.0

2.5 x 10 4

195

Comparative Example 1

Room temperature *

1060

2.7

4.2 x 104

> 220

Comparative Example 2

Room temperature *

290

11.2

1.5 x 10 4

155

* Rip or crack formation when cooling to room temperature after hardening.

As clearly shown in Table 2, the thermal shock resistance is improved by adding EP 871 (flexibilizer). When the amount of EP 871 added exceeded 80%, the heat distortion temperature was significantly reduced.

Example 4

40 g novolack epoxy resin (DEN 431, manufacturer Dow Chemical Co., epoxy equivalent 176), 10 g diglycidyl ester of the linoleic acid dimer (EP 871, manufacturer Shell Co.), 86.4 g diphenylmethane diisocyanate (MDI), Sumidur CD, manufacturer Sumitomo -Bayer Co.), 0.2 g of l-cyanoethyl-2-ethyl-4-methylimidazole (hereinafter referred to as 2E4MZ-CN) and 2.0 g of an epoxysilane coupling agent (KBM 403, manufacturer Shin-etsu Chemical Industry Co., Ltd.) were mixed at 80 ° C. For this purpose, 265 g of melted quartz glass powder (Fuselex RD-8, manufacturer Tatsumori Co.) were added in portions and dispersed with stirring. Degassing was carried out under a reduced pressure of 1 torr for 5 minutes, after which a thermosetting resin composition was obtained.

With this composition, three C-shaped disc test pieces were made. The curing conditions in this case were 115 ° C / 15 h, 140 ° C / 8 h and 180 ° C / 15 h. The heat cycle test was carried out down to -60 ° C; however, there were no cracks.

The heat distortion temperature of the samples was also measured according to ASTM D648-45T and was above 225 ° C; the corresponding bending strengths measured at 20 ° C and 180 ° C according to JIS K-6911 were 1350 kg / cm2 and 985 kg / cm2, respectively. Accordingly, it was found that the composition had excellent strength even at high temperatures.

In addition, when the test pieces mentioned were subjected to heat aging at 225 ° C for 40 days, the weight loss was 2.3% and the flexural strength at 180 ° C was 720 kg / cm2. It was accordingly found that the composition had extremely excellent aging properties in the heat.

Comparative Example 3

In the same manner as in Example 1, a casting resin was produced using the following components:

DEN 431 MDI

2E4MZ-CN

KBM-403

RD-8

50 g 98 g 0.3 g 3.0 g 288 g (51 vol.%)

When measuring the thermal shock resistance of the resin, cracks occurred in all test pieces at 0 ° C. The resin accordingly had only very low thermal shock resistance.

Example 5

15 In the same manner as in Example 1, a casting resin was produced using the following components:

DEN 431 EP 871 MDI

2E4MZ-CN KBM 403 RD-8

25 g 25 g 69 g 0.24 g 2.4 g 222 g (51 vol.%)

25 When measuring the thermal shock resistance of the resin, no cracks were found even at -60 ° C as in Example 1. The bending strength at room temperature was 1180 kg / cm2 and 860 kg / cm2 at 180 ° C; the heat distortion temperature was above 225 ° C. Even after a Hit 30 aging at 225 ° C for 40 days, the bending strength was still 690 kg / cm2 at 180 ° C, the weight loss was 5.6%. The resin accordingly had excellent heat resistance.

Example 6

35 In the same manner as in Example 1, a casting resin was produced using the following components:

40

THE 332 EP 871 MDI

2E4MZ-CN KBM 403 RD-8

25 g 25 g 97 g 0.3 g 3.0 g 323 g (54 vol.%)

45 When measuring the thermal shock resistance of the resin, no cracks occurred even at -60 ° C. The bending strength at room temperature was 1050 kg / cm2, the heat distortion temperature was above 225 ° C.

see example 7

The procedure was as in Example 1, the following components being used:

55

DEN 431 EP 871 MDI

2E4MZ-CN KBM 403 RD-8

10 g 40 g 51.6 g 0.2 g 2.0 g 190 g (51 vol.%)

60

65

When measuring the thermal shock resistance, cracks were formed at -50 ° C. The bending strength was 835 kg / cm2 at room temperature and 580 kg / cm2 at 180 ° C, the heat distortion temperature was 202 ° C.

Example 8

The procedure was as in Example 1, the following components being used:

622 276

6

CY 183 (diglycidyl ester of

Hexahydrophthalic acid)

EP 871 MDI

2E4MZ-CN KBM 403 RD-8

25 g

25 g 72 g 0.2 g 2.4 g 228 g (50 vol.%)

The thermal shock resistance of the resin was so great that it withstood temperature cycles down to -60 ° C. The heat distortion temperature was 215 ° C, the flexural strength at room temperature was 1230 kg / cm2.

Comparative Example 4

EP 871 MDI

2E4MZ-CN KBM 403 RD-8

Example 10

DEN 431 EP 871 MDI

N -methylmorpholine KBM 403 RD-8

DEN 431 EP 871

Xylylene diisocyanate 2E4MZ-CN KBM 403 RD-8

Example 11

25 g 25 g 52 g

0.2 g 2.0 g 234 g (55 vol.%)

The tests were carried out as in Example 1 using the above proportions of the components. The thermal shock resistance of the resulting resin was so high that it withstood the temperature cycles down to -60 ° C. The heat deformation temperature was 180 ° C.

Comparative Example 5 5 The tests were carried out as in Example 1, using butanediol diglycidyl ether DY 022 (manufacturer Ciba Co; epoxy equivalent 137) as the flexibilizer instead of EP 871. Composition:

10th

50 g 40 g 0.2 g 1.8 g 183 g (52 vol.%)

Using the above ingredients, the same tests as in Example 1 were carried out; the thermal shock resistance of the resulting resin was so low that cracks appeared at 0 ° C; the heat deformation temperature was 160 ° C.

Example 9

DEN 431 25 g

EP 871 25 g

MDI 41.4 g 2E4MZ-CN 0.2 g KBM 403 1.8 g

RD-8 171 g (50 vol.%)

The tests were carried out as in Example 1 using the above ratio. The thermal shock resistance of the resulting resin was so high that it withstood temperature cycles down to -60 ° C. The heat distortion temperature was 207 ° C, the flexural strength at room temperature was 1020 kg / cm2.

DEN 431 DY 022 MDI

2E4MZ-CN KBM 403 RD-8

25 g 25 g 112 g 0.3 g 3.2 g 327 g (52 vol.%)

The thermal shock resistance of the resulting resin was so low that the three test pieces only showed cracks when they cooled to room temperature after curing; the thermal shock resistance was accordingly very low.

Comparative Example 6 The tests were carried out as in Example 1, with polypropylene glycol diglycidyl ether (DER 732, manufacturer Dow Chemical Co; epoxy equivalent 320) being used as the flexibilizer instead of EP 871.

DEN 431 DER 732 MDI

2E4MZ-CN KBM 403 RD-8

25 g 25 g 76 g 0.25 g 2.5 g 277 g

The thermal shock resistance of the resulting resin was so low that all three test pieces only showed cracks when cooled to room temperature after curing; the thermal shock resistance of the resin was accordingly very low.

40

Example 12

25 g 25 g 69 g 0.24 g 2.4 g 222 g (51 vol.%)

The tests were carried out as in Example 1 using the above mixing ratio of the components. The thermal shock resistance of the resulting resin was so high that it withstood the temperature cycles down to -60 ° C. The heat deformation temperature was above 225 ° C.

DEN 431

45 g

EP 871

5 g

MDI

92.2 g

2E4MZ-CN

0.3 g

45

KBM 403

2.8 g

RD-8

277 g (51 vol.%)

In the temperature cycle test of the resulting resin, tra

50

only at -50 °

C cracks.

Comparative Example 7

DEN 431

5 g

EP 871

45 g

55

MDI

46 g

2E4MZ-CN

0.2 g

KBM 403

2.0 g

RD-8

180 g (50 vol.%)

The thermal shock resistance of the resulting

60

Resin was only so low that cracks appeared at -30 ° C.

Comparative Example 8

DEN 431

47.5 g

EP 871

2.5 g

65

MDI

95.3 g

2E4MZ-CN

0.3 g

KBM 403

2.9 g

RD-8

283 g (51 vol.%)

7

622 276

In the temperature cycle test of the resulting resin, cracks appeared at -20 ° C.

Examples 13-15 A Diels-Alder adduct obtained by reacting 1 mol of linoleic acid with 1 mol of oleic acid was epoxidized with excess epichlorohydrin, after which a liquid diglycidyl ester compound having an epoxy equivalent of 420 was obtained. The product is referred to below as "Flexibilizer A".

Table 3

Novolack flexibilizer A MDI 2-phenyl melted

Epoxy- (g) (g) imidazole quartz glass powder

Connection * (g) (g)

(G)

Example 13

40

10th

90

0.3

140

Example 14

30th

20th

80

0.3

130

Example 15

20th

30th

65

0.2

115

Comparative Example 9

50

-

100

0.3

150

Comparative Example 10

-

50

42

0.2

92

* Epoxy equivalent 176

Each of the three test pieces was made by pouring a C-shaped disc with the above compositions. The curing conditions for the test pieces were 110 ° C / 5 h and then 180 ° C / 1G h.

For comparison purposes, the tests were also carried out on compositions in which no flexibilizer A had been added as an epoxy compound component, and on compositions in which only flexibilizer A was used as an epoxy compound component.

The results of the temperature cycle test, the flexural strength test and the weight loss after heating for 40 days at 225 ° C. are given in Table 4 for the above compositions.

Table 4

Temperature bending strength (kg / cm2) Weight loss cycle test: initially after 40 d after 40 d

Cracking at 20 ° C including 80 ° C heating to 225 ° C

temperature to 225 ° C (%)

(° C) at 180 ° C

Example 13 -30 1240 980 760 3.5

Example 14 -50 1210 910 630 4.8

Example 15 -60 1120 860 550 5.6

Comparative Example 9 room temperature 1220 1050 910 3.0

Comparative Example 10 1.0 970 230 150 9.3

Examples 16-18 A Diels-Alder adduct obtained by reacting 1 mol of linoleic acid with 1 mol of 5-hexenoic acid and a Diels-Alder adduct obtained by reacting 1 mol of linoleic acid with 1 mol of lindenic acid were also included

excess epichlorohydrin epoxidized, whereupon two liquid diglycidyl ester compounds were obtained. The first product is referred to below as "Flexibilizer B", the latter as "Flexibilizer B".

Table 5

HHPA diglycidyl ester flexibilizer * (g)

(G)

Example 16 25 Example 17 25 Example 18 25

* HHPA: hexahydrophthalic anhydride

MDI

(G)

A 25 70

B 25 70

C 25 70

2-ethyl melted

4-methyimidazole quartz glass powder (g) (g)

0.1 220

0.1 220

0.1 220

The thermal shock resistance, flexural strength and weight loss of the same by curing the thermosetting resin composition shown in Table 5 among them

Conditions as in cured products obtained in Example 13 are shown in Table 6.

622 276

Table 6

temperature

Flexural strength kg / cm2

Weight loss cycle test:

initially after 40 d after 40 d

Crack formation

at 20 ° C at 180 ° C

Heat

Heating temperature

to 225 ° C

to 225 ° C

CC)

-

at 180 ° C

(%)

Example 16 Example 17 Example 18

<-60 -60 -10

1220 1200 1290

880 760 790

620 610 490

3.8 4.0 4.2

Table 6 shows that the Diels-Alder adduct (with 25 C atoms) made from linoleic acid and linden acid shows little influence on the results of the temperature cycle test.

Examples 19-21 The diglycidyl ester of the linolenic acid dimer was prepared by epoxidizing the dimeric acid obtained from linolenic acid by Diels-Alder reaction with epichlorohydrin. The product is referred to below as "Flexibilizer D".

The properties of the thermosetting resin compositions listed in Table 7 are shown in Table 8. The curing conditions were 110 ° C / 15 h, 140 ° C / 8 h and then 180 ° C / 15 h.

Table 7

Novolack epoxy compound * (g)

Flexibilizer A (g)

MDI

(G)

2-phenyl

imidazole

(G)

melted

Quartz glass powder

(G)

Example 19

40

10th

85

0.14

230

Example 20

30th

20th

75

0.13

218

Example 21

20th

30th

60

0.11

187

Comparative Example 11

50

-

93

0.14

243

Comparative Example 12

-

50

38

0.09

150

: Epoxy equivalent 176

Table 8

temperature

Flexural strength kg / cm2

Weight loss

cycle test:

initially

after 40 d after 40 d

Crack formation

at 20 ° C

at 180 ° C

Heat

Heat

temperature

to 225 ° C

to 225 ° C

(° C)

at 180 ° C

(%)

Example 19

<-60

1190

830

480

2.8

Example 20

<-60

1110

760

450

3.7

Example 21

<-60

1050

690

440

4.2

Comparative Example 11

0

1160

975

620

2.2

Comparative Example 12

-10

880

250

180

7.1

Examples 22-25 The thermosetting resin compositions shown in Table 9 were prepared using the diglycidyl esters of the corresponding dimeric acids, which consist of the dimeric acid from linolenic acid and 5-hexenoic acid (flexibilizer E), from the dimeric acid of linolenic acid and lindenic acid (flexibilizer S ) or from the dimeric acid from arachidonic acid and selacholeic acid (flexibilizer G).

Table 9

Diglycidyl ester flexibilizer MDI 2-ethyl-melted from HHPA * (g) (g) 4-methylimidazole quartz glass powder

(g) (g) (g)

Example 22 25 D 25 70 0.1 220

Example 23 25 E 25 70 0.1 220

Example 24 25 F 25 70 0.1 220

Example 25 25 G 25 70 0.1 220

HHPA: hexahydrophthalic anhydride

9

622 276

The properties of the cured products obtained by curing the above Example 19 are shown in the table compositions under the same curing conditions as in FIG. 10.

Table 10

Temperature / bending strength kg / cm2 weight loss cycle test: initially after 40 d after 40 d

Cracking at 20 ° C at 180 ° C Heating heating temperature to 225 ° C to 225 ° C

(° C) at 180 ° € (%)

Example 22 <-60 1120 770 510 3.9

Example 23-20 1250 890 "530 4.7

Example 24 -60 1350 840 470 4.3

Example 25 * - - - - _

* The uniformly dispersed state according to the invention could not be achieved since the components were not miscible with one another.

As clearly shown in the table above, the dimeric acids (with 44 carbon atoms) of arachidonic acid and selacholeic acid did not provide any cured products which met the requirements according to the invention.

Examples 26-28 By reacting a polycarboxylic acid with excess epichlorohydrin in the presence of sodium hydroxide, a polyglycidyl ester with an epoxy equivalent of 390 was obtained; the polycarboxylic acid was prepared by heating a mixture of 284 g (1 mol) of linoleic acid and 1.4 g of di-tert-butyl peroxide at 220 ° C. for 5 hours. The product is referred to below as "Flexibilizer H".

Table 11

Novolack flexibilizer H MDI 2-phenyl melted

Epoxy- (g) (g) imidazole quartz glass powder

Connection * (g) (g)

(G)

Example 26

40

10th

82

0.13

232

Example 27

30th

20th

77

0.13

224

Example 28

20th

30th

66

0.12

204

Comparative Example 13

50

-

100

0.15

264

Comparative Example 14

-

50

44

0.10

165

* Epoxy equivalent 176

The properties of the cured products obtained by curing the above compositions are shown in Table 12 under the same conditions as in Example 19.

Table 12

temperature

Flexural strength kg / cm2

Loss of weight

cycle test:

initially

after 40 d after 40 d

Crack formation

at 20 ° C

at 180 ° C

Heat

Heat

temperature

to 225 ° C

to 225 ° C

(° C)

at 180 ° C

(%)

Example 26

-60

1310

870

660

2.9

Example 27

<-70

1190

790

590

3.4

Example 28

<-70

980

680

550

3.9

Comparative Example 13

Room temperature

1280

1010

880

2.4

Comparative Example 14

10th

760

220

120

8.5

Example 29-32 with Linolenic Acid (referred to as Flexibilizer J) and with Sela-

There were obtained diglycidyl esters of polycarboxylic acids - oleic acid (referred to as flexibilizer K) containing 5-hexenoic acid (referred to as flexibilizer I).

622 276

10th

Table 13

Diglycidyl ester of HHPA * (g)

Flexibilizer (g)

MDI

(G)

2-ethyl

4-methylimidazole (g)

melted

Quartz glass powder

(G)

Example 29 25 H 25

Example 30 25 125

Example 31 25 J 25

Example 32 25 K 25

* HHPA: hexahydrophthalic anhydride

The properties of the by curing the above composition under the same curing conditions as in

70 70 70 70

0.1 0.1 0.1 0.1

220 220 220 220

Game 19 obtained hardened products are listed in Table 14.

15

Table 14

temperature

Flexural strength kg / cm2

Weight loss cycle test:

initially after 40 d after 40 d

Crack formation

at 20 ° C at 180 ° C

Heat

Heating temperature

to 225 ° C

to 225 ° C

rc)

at 180 ° C

(%)

Example 29 <-60 1380 820 630 4.2

Example 30 -10 1370 1050 740 3.9

Example 31 <-60 1403 865 590 4.8

Example 32 * - -

"The uniformly dispersed state according to the invention could not be achieved since the components were not miscible with one another.

Example 33

With copper flat wire (10 x 20 x 450 mm) a model coil [(3), cf. 4 (a)], the shape of which corresponded to a diamond coil cut in half for rotating electrical machines. 17 such model coils were arranged as in Fig. 4 (b) and potted with the thermosetting resin composition (4) having the following composition. The model coil for rotating electrical machines mentioned had the dimensions 100 x 100 x 1000 mm. After pouring in at 80 ° C and 1 atm, curing was carried out at 110 ° C / 1.5 h, at 140 ° C / 8 h and then at 180 ° C / 15 h.

Composition:

Novolack epoxy resin (epoxy equivalent 174) 80 g

Polyglycidyl ester of linoleic acid dimer 20 g

(Epoxy equivalent 430)

MDI 172 g l-cyanoethyl-2-ethyl-3-ethylimidazole 0.2 g

KBM 403 4.0 g melted quartz glass powder 530 g

When the temperature cycle test was carried out 20 times from 180 ° C / 2 h to -30 ° C / 2 h on the above model coil for rotating electrical machines, no cracks or cracks were found in the casting resin.

Comparative Example 15 In the resin composition of Example 33, 100 g of the novolak epoxy resin (epoxy equivalent 174) were used without the addition of the polyglycidyl ester of the linoleic acid dimer. In this case, cracks occurred at the places where the casting resin was in contact with the copper coil when the model coil for rotating electrical machines was cooled to room temperature after hardening.

This model coil as in Example 33 was also made 40 using the epoxy resin composition described below, which was expected to have a comparatively good thermal shock resistance. When the model coil was cooled to room temperature after curing, however, cracks in the casting resin appeared halfway up from the top of the coil.

Composition:

3,4-epoxycyclohexylmethyl- (3,4-epoxy) -

cyclohexane carboxylate 60 g so bisphenol A epoxy resin (epoxy equivalent 410) 40 g

Vinylcyclohexene dioxide 20 g

Methyl tetrahydrophthalic anhydride 240 g

Benzyldimethylamine 1 g

Quartz glass powder 540 g

55

2 sheets of drawings

Claims (5)

622 276 PATENT CLAIMS 1. A thermosetting resin composition comprising the following components: a) 1 equivalent, based on an existing isocyanate compound, of a polyfunctional epoxy compound which contains 10-80% by weight of a polyglycidyl ester of a fatty acid, b) 1.5-5 equivalents, based on the epoxy compound mentioned, a polyfunctional isocyanate compound, c) 0.01-10% by weight of a curing catalyst, based on the total weight of the polyfunctional epoxy compound and the polyfunctional isocyanate compound. 2. Resin composition according to claim 1, characterized in that it contains additives or fillers. 3. A thermosetting resin composition according to claim 1 or 2, characterized in that the polyfunctional epoxy compound contains 10-80% by weight of a polyglycidyl ester of a fatty acid with 25-43 carbon atoms. 4. A thermosetting resin composition according to claim 1 or 2, characterized in that the polyfunctional epoxy compound contains 20-60% by weight of a polyglycidyl ester of a fatty acid. 5. Use of the thermosetting composition according to claim 1 for the production of hardened products, characterized in that the thermosetting composition is hardened at a temperature of 50-250 ° C.